There are numerous Caulking Guns disclosed in the prior art.
U.S. Pat. No. 2,102,939 Bishop PA1 U.S. Pat. No. 2,367,347 Good PA1 U.S. Pat. No. 2,732,102 Ekins PA1 U.S. Pat. No. 4,126,251 Subwick PA1 U.S. Pat. No. 4,009,804 Costa
The after drip of the caulking compound in at least one of the patents mentioned is reduced, but because of the impeded rearward motions of the plunger, the after drip is not completely stopped.